[waffle]Radio button should announce search engine name

The radio button should announe the search engine name when selected
while using the screen reader.

Recording: http://b/330929792#comment2
Fixed: b:330929792, b:331593799
Change-Id: Iad4d85bc7f3350ec9168de7e6b4992ecb17f5741
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5401755


Auto-Submit: Jack Yammine <jyammine@google.com>
Commit-Queue: Nicolas Dossou-Gbété <dgn@chromium.org>
Reviewed-by: Nicolas Dossou-Gbété <dgn@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1278990}